Graphite crucible



Dec. 9, 1924.. 1,518,818

E. RIETZ GRAPHI TE CRUC I BLE l Filed Nv. 22, 1916 specification. v .y

My present invention relates to a new.

Patented Dec. 9,1924;

FFlcs.

Ennemi am'rz, orA sAo PAULO, BRAZIL.'

. GRAPHITE oRUoiBnri Application filed November 2 2, 1916: Serial No. 132,876.

To all whom z'tmoy concern.'-

Be it known that I, EDUARD ject of the King of Prussia, residlngat Sao Paulo,'in the Republic of Brazil, 'have in vented 'a -new and useful improved Graphite Crucible, 'of which the following is a graphite Crucible. The object of the "new crucible is to oder greater resistance. to slags, chemical reagents and the like and to assure aconsiderably longer time of use than existing graphite Crucibles.

The characteristic feature of the new crucible is that in addition to graphite and other lireproof substances, such as clay, chamotte, or sand, compounds of the so called titanium group of metals, that is compounds of zirconium and thorium are-used. The amount of 'the compounds of the titanium group "of metals added is between' 5 to 40%, and the oxides or salts or tlie' ores may7 be used.

' The zirconium compoundshave been found to be specially suitable for the purpose. Zirconium oxides, either -natural v. or artificial, o r zirconium silicates, natural or artificial, o r other salts may 'be used. These :substances are preferably addedto the' other constituents of the crucible, such as graphite, clay, chamotte, ysand or broken crucibles,

in a powdered' condition. The various substances are mixed in a powdered' form and from the mixture the crucible is formed.-

Special binding agents, sucli'fas fluxes', or

the like, may be added in order to facilitate the moulding. The crucible is formed, and',

' graphite and compoundsv ofthe titanium if necessary, it is burnt. A Vspecial mixture consists, for example, of` parts of zirco-` nium, 40 parts of graphite, 25 parts of clay.

By adding oxides of the titanium group the clays otherwise used in connection with graphite are partly replaced, so that less clay, chamotte, sand is .required than usual.

The proportions citedc'an` ofcourse be altered. For example 10% 'zirconium 70 parts of graphite and 20 parts of clay, `chaiiiotte, and sand may be lused. After being formed the crucible'is' burnt, forY example,

graphite, 'compounds of the rare earths, such at a temperaturevof'1000o C.r

Incertain cases. zirconium oxide and;

group should be used and that in 4individual Riii'rz, a sub- V -cases, especially zirconium and selectively also thorium-should be utilized.

In -carrying out the inventionv a single compound may be, used, butj-still several com-` pounds offthe titanium group may be used together. l

consists in providing acruciblemade from a mixture of graphite, clay, zirconium or an oxide of the titaniumgroup'witli a layer on the inner side made `froin'a mixture of compounds of the titanium group of metals, to Whicha binding agent has beenl added, and infburning this layer at a suitable temperature. ABy so doing the tireproof and acid prooi roperty of the crucible is increased. In t e accompanying drawing which is a sectional view .of a cruciblethe crucible is indicated at l and the inside layer of rare earth and binder is indicated at v2. Fireproof `vessels have already been made from )zirconium oxide and thorium oxide 'without graphite.v Both pure and natural zirconium oxides have been used for thev purpose. Such'lireproof vessels (crucibles,

stones, inuiieS) are however not durable. My present invention does not relate to the production of all kinds of vessels' out of zirconium compounds, but to crucibles which contain graphite, the usual additional substances -`and oxides*` of the titanium group.

4. The described 'crucible consisting of* graphite, ireproof substances such as for instance', 'clay,.an.d cha-motte, and zirconium compounds.

5. The described crucible consisting of as oxide of zirconium and oxide ofthorium 6. lThe described ,crucible consisting of A One manner'of making the new Crucible y I ing agent.

graphite, ireproof substances, compounds of graphite, reproo'f suivistances,l zirconium the titanium group such as oxide of zircocompounds, and a layer of zirconium comnium and oxide of thorium, and a layer pounds with a binding agent. f of compounds of therare earths with a bind- Inl testimony whereof I have signed my v name toithis specification in' the -presence 15 7 The described vCrucible consisting of of' two subscribing vvi'tliess'eaV Graphite and zirconium compounds with a' EDUARD RIETZ; ayerof'zirconum'compounds and-a.J bindlWitnesses: ing agent. FRANCIS R. STEWART, 1 8. The described Crucible consisting of l vW.V;-BRI1-IK11IA1-L 

